The present invention relates to a mechanical filter which separates a fluid flow of a mixture of oil and water into separate components which can then be further managed. The filter can be deployed as either a fixed or transportable unit and sized to separate either a small or large volume flow of mixed oil and water.
Conventional methods for separating a fluid mixture of oil and water involve placing the mixture in a tank or other container until the oil floats to the top of the tank where it may be skimmed off. One commonly used separator is referred to as an xe2x80x9cAPIxe2x80x9d separator and consists of a relatively long, narrow tank, frequently open-topped, in which the mixture enters at one end in a continuous flow and is removed at the other end by the oil flowing out an upper discharge and the water flowing out a lower discharge. Other approaches use either open or closed top tanks which hold the mixture until the oil separates by floating to the top. After a predetermined time, the water and possibly any sediments are removed from the bottom of the tank and the oil is removed from the top, then the tank is refilled for another cycle.
Biological treatment systems are also used to consume oil from oil-water mixtures but have a relatively slow process time. Other approaches include additions of chemical or steam to aggregate or evaporate the oil component. These systems are not energy efficient and require external sources of chemicals or steam. What is needed is a flow-through filter which requires minimal additional support or supplies and quickly and efficiently separates petroleum hydrocarbons from water.
The present invention is an improved filtering device for separating any mixture of two immiscible fluids having different specific gravities, such as separating a raw fluid mixture of oil and water into two relatively pure fluids which can then be separately managed. The filter can be used with either a gravity or pumped in-feed flow, and can be constructed in a range of sizes from easily transportable units to large fixed installations. When separating a mixture of oil and water, the filter operates in an external holding tank of water, which has the higher specific gravity, in which it is nearly entirely submerged. The filter uses a combination of hydrostatic pressure and head pressure to exploit the difference in specific gravity of the two fluids, efficiently effecting a separation.